A new mutation in Muir-Torre syndrome associated with familiar transmission of different gastrointestinal adenocarcinomas.

Hereditary Nonpolyposis Colorectal Carcinoma (HNPCC) is the most frequent inherited disease which can lead to the development of tumors in the colon and other locations. Its genetic basis is related to the germline mutation of the Mismatch Repair (MMR) genes. Muir-Torre syndrome is considered one of the subtypes of this disease, in which the HNPCC tumor spectrum is frequently associated with sebaceous carcinoma of the skin or keratoacanthoma. A 57 years old male patient is presented with a mucinous carcinoma of the caecum and an adenocarcinoma of the pancreas head. A malignant sebaceous carcinoma was removed from his left neck area. His family history was significant for two cases of colon carcinoma, two cases of stomach cancer and a case of metacron endometrial and skin tumor as well. Both the colon carcinoma and the skin tumor proved to be microsatellite unstable. An Arg>Pro switch missense mutation was found in codon 265 of the hMLH1 gene. This error was found in 4 other members of his family. The detected genetic alteration was considered pathogenic and was not published yet in English literature. The significance of this particular case is the rare tumor association in a patient with Muir-Torre syndrome (MTS). In cases of sebaceous skin lesions, evaluation of family history is of utmost importance in the early detection of HNPCC and in the follow up care of family members with the particular mutation.